Mana not being added to pool

[ask3m]

Every time I tap a land to cast a spell, it doesn't register that mana is being added to my mana pool, making the game unplayable for me. How does this get fixed?

[gcb]

Do you have mana auto payment on? (during a game, press right click and look into the "Mana options" (or some similar name) submenu)